/*
 * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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 *
 */

package com.sun.source.util;

import java.io.IOException;

import javax.annotation.processing.ProcessingEnvironment;
import javax.lang.model.element.Element;
import javax.lang.model.type.TypeMirror;
import javax.lang.model.util.Elements;
import javax.lang.model.util.Types;
import javax.tools.JavaCompiler.CompilationTask;
import javax.tools.JavaFileObject;

import com.sun.source.tree.CompilationUnitTree;
import com.sun.source.tree.Tree;
import com.sun.tools.javac.api.BasicJavacTask;
import com.sun.tools.javac.processing.JavacProcessingEnvironment;
import com.sun.tools.javac.util.Context;

/**
 * Provides access to functionality specific to the JDK Java Compiler, javac.
 *
 * @author Peter von der Ah&eacute;
 * @author Jonathan Gibbons
 * @since 1.6
 */
@jdk.Exported
public abstract class JavacTask implements CompilationTask {

  /**
   * Get the {@code JavacTask} for a {@code ProcessingEnvironment}.
   * If the compiler is being invoked using a
   * {@link javax.tools.JavaCompiler.CompilationTask CompilationTask},
   * then that task will be returned.
   *
   * @param processingEnvironment the processing environment
   * @return the {@code JavacTask} for a {@code ProcessingEnvironment}
   * @since 1.8
   */
  public static JavacTask instance(ProcessingEnvironment processingEnvironment) {
    if (!processingEnvironment.getClass().getName().equals(
        "com.sun.tools.javac.processing.JavacProcessingEnvironment")) {
      throw new IllegalArgumentException();
    }
    Context c = ((JavacProcessingEnvironment) processingEnvironment).getContext();
    JavacTask t = c.get(JavacTask.class);
    return (t != null) ? t : new BasicJavacTask(c, true);
  }

  /**
   * Parse the specified files returning a list of abstract syntax trees.
   *
   * @return a list of abstract syntax trees
   * @throws IOException if an unhandled I/O error occurred in the compiler.
   * @throws IllegalStateException if the operation cannot be performed at this time.
   */
  public abstract Iterable<? extends CompilationUnitTree> parse()
      throws IOException;

  /**
   * Complete all analysis.
   *
   * @return a list of elements that were analyzed
   * @throws IOException if an unhandled I/O error occurred in the compiler.
   * @throws IllegalStateException if the operation cannot be performed at this time.
   */
  public abstract Iterable<? extends Element> analyze() throws IOException;

  /**
   * Generate code.
   *
   * @return a list of files that were generated
   * @throws IOException if an unhandled I/O error occurred in the compiler.
   * @throws IllegalStateException if the operation cannot be performed at this time.
   */
  public abstract Iterable<? extends JavaFileObject> generate() throws IOException;

  /**
   * The specified listener will receive notification of events
   * describing the progress of this compilation task.
   *
   * If another listener is receiving notifications as a result of a prior
   * call of this method, then that listener will no longer receive notifications.
   *
   * Informally, this method is equivalent to calling {@code removeTaskListener} for
   * any listener that has been previously set, followed by {@code addTaskListener}
   * for the new listener.
   *
   * @throws IllegalStateException if the specified listener has already been added.
   */
  public abstract void setTaskListener(TaskListener taskListener);

  /**
   * The specified listener will receive notification of events
   * describing the progress of this compilation task.
   *
   * This method may be called at any time before or during the compilation.
   *
   * @throws IllegalStateException if the specified listener has already been added.
   * @since 1.8
   */
  public abstract void addTaskListener(TaskListener taskListener);

  /**
   * The specified listener will no longer receive notification of events
   * describing the progress of this compilation task.
   *
   * This method may be called at any time before or during the compilation.
   *
   * @since 1.8
   */
  public abstract void removeTaskListener(TaskListener taskListener);

  /**
   * Get a type mirror of the tree node determined by the specified path.
   * This method has been superceded by methods on
   * {@link com.sun.source.util.Trees Trees}.
   *
   * @see com.sun.source.util.Trees#getTypeMirror
   */
  public abstract TypeMirror getTypeMirror(Iterable<? extends Tree> path);

  /**
   * Get a utility object for dealing with program elements.
   */
  public abstract Elements getElements();

  /**
   * Get a utility object for dealing with type mirrors.
   */
  public abstract Types getTypes();
}
